“The high rising terminal (HRT), also known as upspeak, uptalk, rising inflection, upward inflection, or high rising intonation (HRI), is a feature of some variants of English where declarative sentence clauses end with a rising-pitch intonation, until the end of the sentence where a falling-pitch is applied.”

My short answer would be, no I do not believe they realize that they are ending each sentence in the question. If this is part of their normal speech pattern, odds are they are going to use the same speech patterns when there public speaking.

Any speaker demonstrating this habit could benefit from a Toastmaster’ s style evaluation. The lilt and their speaking would be drawn to their attention and then they would try to reduce it the next time they speak. The speakers could also benefit from making a digital recording either audio or video to point out the effect this habit has on the speaking effectiveness.

Like any other skill it takes time to practice and to reduce the tendency to lilt.